To make a simple analogy, it is a bit like how one can get certain effects from alcoholic beverages when wide awake vs. when tired or stressed vs. in combination with other drugs such as barbiturates or anti-depressants.

He said he'd done a stint in a rehab clinic in Arizona and was recovering from addictions to alcohol, sleeping pills and barbiturates — habits he blamed on the pressures of the high-stakes fashion industry.

Drugs which are distributed in fat, e.g., barbiturates, will have an increased volume of distribution. 10 Drugs which distribute in body water, e.g., lithium, would have a lower volume of distribution, and would consequently need to be administered in a lower dose. 10